What happened
In the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix a crash in UFFDIO_MOVE when PMD is a migration entry When UFFDIO_MOVE encounters a migration PMD entry, it proceeds with obtaining a folio and accessing it even though the entry is swp_entry_t. Add the missing check and let split_huge_pmd() handle migration entries. While at it also remove unnecessary folio check. [surenb@google.com: remove extra folio check, per David]
Affected versions
Linux: adef440691bab824e39c1b17382322d195e1fab0 through before bb81c18dbd42650c844e160cafa7cbb20243a96a (git); adef440691bab824e39c1b17382322d195e1fab0 through before 1202abad7a7ccd28c426d2844771a387b07629a4 (git); adef440691bab824e39c1b17382322d195e1fab0 through before 7f1101a0a181243ad587ececdffc4845f035549f (git); adef440691bab824e39c1b17382322d195e1fab0 through before aba6faec0103ed8f169be8dce2ead41fcb689446 (git); 6.8 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.